Re: [PATCH v2] .gitlab-ci.d/crossbuilds.yml: Force 'make check' single-threaded for cross-i686-tci

[Peter Maydell]

On Fri, 13 Sept 2024 at 13:24, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> On Thu, 12 Sept 2024 at 16:10, Peter Maydell <peter.maydell@linaro.org> wrote:
> >
> > The cross-i686-tci CI job is persistently flaky with various tests
> > hitting timeouts.  One theory for why this is happening is that we're
> > running too many tests in parallel and so sometimes a test gets
> > starved of CPU and isn't able to complete within the timeout.
> >
> > (The environment this CI job runs in seems to cause us to default
> > to a parallelism of 9 in the main CI.)
> >
> > Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> > ---
> > If this works we might be able to wind this up to -j2 or -j3,
> > and/or consider whether other CI jobs need something similar.
>
> I gave this a try, but unfortunately the result seems to be
> that the whole job times out:
> https://gitlab.com/qemu-project/qemu/-/jobs/7818441897

...but then this simple retry passed with a runtime of 47 mins:

https://gitlab.com/qemu-project/qemu/-/jobs/7819225200

I'm tempted to commit this as-is, and see whether it helps.
If it doesn't I can always back it off to -j2, and if it does
generate a lot of full-job-timeouts it's only me it's annoying.

Looking at the timed-out job it looks like it just took a lot
longer on the compile phase... (Though it's hard to say because
the fact we use "make all check-build" in our gitlab CI config
means gitlab treats this as all one step when it adds time
annotations, and you can't separate time-for-compile from
time-for-tests.)

-- PMM